Chimerix

Smallpox

In addition to the company's development of its lead candidate, CMX001, for transplant recipients, CMX001 is also being developed as a medical countermeasure in the event of a smallpox release, with the potential to provide an important therapeutic option for the 80 million people in the U.S. currently estimated to be immunocompromised, or a household contact of a contraindicated individual, and thus not candidates to receive a smallpox vaccine (for additional information click here). Chimerix has received federal funding for the development of CMX001 as a medical countermeasure against smallpox from the National Institute of Allergy and Infectious Diseases under Grant No. U01-A1057233 and from the Biomedical Advanced Research and Development Authority (BARDA), Office of the Assistant Secretary for Preparedness and Response, Office of the Secretary, Department of Health and Human Services, under Contract No. HHSO100201100013C.

An acute, highly contagious disease caused by variola virus, a member of the orthopoxvirus family, smallpox is a disease of significant interest to government agencies because of concerns that the virus could be used for bioterrorism.

In vivo, the antiviral activity of CMX001 has been characterized in mice infected with ectromelia, vaccinia, and cowpox viruses and in rabbits infected with rabbitpox. In each model, a dose of CMX001 was identified that provided protection against challenge with a lethal viral inoculum. Higher oxidative metabolism of CMX001 in monkeys necessitates efficacy trials in this species with cidofovir and extrapolation of human doses for CMX001 through the active antiviral cidofovir diphosphate. Since cidofovir and CMX001 produce the same active antiviral species in vivo (cidofovir diphosphate), it can be used as a product surrogate for CMX001 to test activity in monkeys. Cidofovir has provided protection in lethal models of monkeypox and variola (smallpox) infection in non-human primates. Chimerix is actively pursuing development of CMX001 for the prevention and treatment of smallpox under the "Animal Efficacy Rule," which allows the U.S. Food and Drug Administration to rely on efficacy data from animal models of human disease in the development and approval of a compound.